Video playback problems after installing video editing suite - Please help!

[abeelandig]

I recently installed Sony Vegas Movie Studio Platinum 10 from http://www.sonycreativesoftware.com on Win XP/SP3.
However shortly after I installed it, I found that Windows Media Player (WMP) playback of video files became corrupted with some files no longer playing at all (just a black screen with sound), to others with choppy video playback or distorted picture playback.
Uninstalling the Sony software made no difference.
I was able to get .avis and some .wmv files to play again by allowing WMP to download the required codecs, however at the moment, WMP player playback of .wmv files with the 'Windows Media Video 9' codec are corrupted. The picture just plays back with rolling horizontal lines down the screen, although sound is unaffected.
VLC player is able to play these files ok though, presumably since it comes with it's own codecs.
Uninstalling and reinstalling the 'windows media video 9 vcm codec' from Microsoft made no difference.
On the Sony Vegas site all I could find was a reference to choppy mpeg playback which was explained by:

Sony Ceative Software applications install an MPEG Directshow decoder so you can preview your MPEG files in Windows Media Player. Most of the time this works just fine, but some other applications may misbehave with the MainConcept MPEG Directshow reader so here's how to disable it:

1. Find the files "mcdsmpeg.ax" and "mcspmpeg.ax"
2. rename them to: "mcdsmpeg.ax.hide" and "mcspmpeg.ax.hide"

However, I don't have these files on my computer, and, anyway mpeg playback was unaffected for me.

Any ideas on how to fix 'Windows Media Video 9' playback?
Thanks in advance for any advice or info.

[Bonie81]

Many professional softwares take over installed codecs, and mess-up win registry.
If you were successfully playing videos in WMP prior to the installation of particular professional suite, the chances are broken codec or registry mess. There is a small tool here on Video Help (I have used it a long.. long ago...) which fixes all broken codec issues.

But, doing this may affect professional suite codec and it's registry as well!

[abeelandig]

Hi Bonie81,
Do you remember the name of the tool which fixed the codec issues?